Swellable seals are known for use in many applications and function by swelling to create a seal upon exposure to an activating medium, typically a fluid medium. Such swellable seals are used in the oil and gas industry. For example, downhole swellable seals are known for use in creating annular seals, typically called packers, such as between a tubular and a wall of an open or cased bore. Swellable seals or packers may be used with a variety of oil field tubulars or base pipes, such as casing, liner, production tubulars or the like. Such tubulars or base pipes are typically coupled together, for example via threaded connectors or the like, in end-to-end relation to form a tubing string. Swellable seals may be strategically positioned along the length of the tubing string for a desired purpose, such as for zonal isolation.
A swellable seal may be provided on a tubular by directly bonding a swellable material to the tubular, or alternatively by bonding a swellable material to a sleeve which in turn is installed onto the tubular from one end thereof. In both cases a degree of pre-installation of the seal is typically required prior to employment of the tubular. For example, where the tubular is used to form part of a tubing string the swellable seal is installed before the tubular is connected to the tubing string. In certain circumstances the presence of the pre-installed seal may interfere with tubular handling. For example, the seal may prevent sufficient gripping of the tubular by torquing tools used to screw together adjacent lengths of pipe, lifting mechanisms, or the like.
Preinstalled swellable seals, whether directly bonded to the tubular or provided on sleeves, may suffer from the above noted and other problems due to limited available space on the base tubular. That is, the tubular may be formed or arranged such that a suitable location for a swellable seal is severely restricted, which may prevent the use of a seal altogether. This problem occurs in many situations, and is exemplified in Expandable Sand Screen (ESS) tubulars where the screens may extend over the majority of the surface of the tubular, leaving little space to accommodate a swelling seal in a currently known manner.
Furthermore, the architecture of the tubular or tubing string may make it difficult to appropriately secure a sleeve-type swellable seal against unwanted displacement. Such unwanted displacement may cause damage to other components of a tubular or tubing string, such as a screen material of an ESS tubular.